Broach-operating mechanism



R. R. LAPolNTE.

BROACH OPERATING MECHANISM.

I APPLICATION FILED DEC.13,1918 4 1,362,536. Patented De. 14, 1920.

2 SHEETS-SHEE] I.

UTM

['l l 11,. 11i, m ku H. R. LAPOINTE.

BROACH OPERATING MECHANISM.

APPLICATION FILED' DEC. 13, i918.

1,362,536. Patented Dec. 14,1920.

2 SHEETS-SHEE'I 2.

Q [Q`g r I .y z

5o Q we E I Q I NN a i a UNITED 4STATES PATENT OFFICE. i

RALPH R. LAPOINTE, OF HUDSON, MASSACHUSETTS, ASSIGNOR 0F ONE-HALF TO BENJAMIN F. LEVY, OF BOSTON, MASSACHUSETTS.

BROACH-OPERATING MECHAN ISM.

Specification of Letters Patent. Patented Dec. 14, 1920 Application led December 13, 1918. Serial No. 266,645.

T o a'ZZ 'whom it may concern:

Be it known that I, RALPH-RLAPOINTE, a citizen of the United States, and resident of Hudson, county of Middlesex, Commonwealth of Massachusetts, have invented an Improvement in Broach-Operating Mechanisms, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts in each of the several views.

This invention relates to broaching machines and particularly to machines of the horizontal draw-cut type. More especially the invention has to do with a machine of this type wherein the broach draw head is operated by a plurality of screws spaced apart at opposite sides of the broach holding socket so that the operative pull in the broaching operation is 'equally and evenly distributed between the screws', and so that the broach head moves evenly and freely on its ways without tendency to binding vor undue friction. One important object of the invention is to provide improved operating mechanism for such plurality of screws that is simple, strong, and reliable in action and capable of easy and convenient control. A further object is to provide improved and simplified ,operating gearing that is capable of use either wit-h stationary operating screws onwith rotary screws. The forego; ing and other objects and advantages of the invention will more fully appear from the following detailed description, and the distinctive features of novelty will be pointed out in the appended claims.

Referring to the drawings:

Figure 1 is a side elevation of a machine constructed in accordance with our invention, an intermediate portion being broken awa Fig. 2 is a lengthwise vertical section approximately. on line 2--2 of Fig. 3;

Fig. 3is a horizontal section on line 3-3 of Fig. 1;`

Fig'. 4 is a transverse vertical section on line 4 4 of Fig. 3; and

Fig. 5 is a horizontal section of the rear portion of the machine showing a modified form wherein the screws are not rotated. 1

The bed frame 10 of the machine extends horizontally, having at its forward end a vertical face 11 tov which the work holding face plate is adjustably secured, and having at its rear an enlarged housing v12 in which the operating gearlng is mounted. Intermediate its length the bed frame is equipped with horizontally extending guide ways at its sides which may be in the form of rails 13 for supporting and guiding a draw head 14 for its sliding operative movement. The

vdraw head 14: has a passage 15 centrally therethrough to receive a broach holder 16 to which is secured the tang of thebroach B, this holder being as shown held in place by interengagement with a suitable threaded and headed bushing 17 fitted in said passage. Engaged with the draw head 14 at each side of the broach holding socket provided by the passage 15, are operating screws 18, 18, these being spaced equally at each side of the socket 15 and in a common plane therewith inner portions of the screws are formed as plain shafts 22, 22 fitted in bearings of 'a thickened web 2.3 extending transversely at an intermediate rear portion of the bed. The screw shafts are shoulderedas indicated at'24 just in front of the transverse web 23 and have fitted thereon thrust collars 25 with interposed anti-friction bearings 26 between said. collars and bearing faces at the front of the web 23. The screw shaft portions 22, 22a extend through the web 23 into the gear housing 12 where they have keyed thereon driving gears 27, 27a, the ends of the shafts having enlarged heads 28 which are fitted into recessed seats 29 of said gears.

` The engagement ofy the heads 28 with the gears 27, 278| constitutes means for receiving f and taking up the operative thrusts on the screws and interposed between said gears and the web 23 are anti-friction bearings 30. As will be lseen from Figs. 2 and 3 the gear 27 is mounted behind the 'gear 27at so that these gears can overlap'. This permits the gears 27, 27l to be of adequate size for the purpose required and also'permits driving engagement with both these gears by an elongated pinion 31 which is fast on a clutch' sleeve 32 rotatably and slidably mounted on a shaft 33 fixed at its ends in the machine frame. Thus the gears 27 27al are both rotated in the same direction and the screws 18, 18aL will hence be of the same pitch. For a purpose that will presently appear the teeth of the pinion 31, and also of the gears 27, '27 meshing therewith, are preferably inclined or spiral as shown in Figs. 2 and 3. Rotatably fitted on the shaft 33 at one side of the clutch sleeve 32, z'. e., to

the left as seen in Fig. 2 is a clutch head 34, the hub of which has keyed thereto a spur gear 35 which is in driven en agement with a pinion 36 fast on a shaft `3 mounted for rotation and limited sliding movement in bearings of the Kmachine base. The shaft 37 also has keyed lthereon, but so that it can` slide therethrough, a pinion 38 in driving engagement through an intermediate gear 39 with a gear, 40 loosely mounted on the shaft 33 and having a clutch face 41 on its inner side engageable by the clutch face at the outer end of the clutch sleeve 32. The shaft 37 extends without the machine base where it has keyed thereon a flaring disk 42 equipped with a friction face 43 engageable by a conical clutch seat in a prime driving wheel 44 loosely mounted on a bushing 45 encircling the shaft 37 and extending out- .Ward from a sleeve of the machine base.

The clutch facep43 is normally held in operative engagement with the drive Wheel 44 by a compression spring 46 mounted on the shaft 37 and reacting against a collar 47 fixed thereon. The shaft 37 may be moved endwise to disengage saidfriction clutch members by a swinging arm 48 fixed to a shaft 49 journaled transversely in the base, and when the shaft 37 is thus shiftedto the right as' seen in Fig. 2, the flaring disk 42 after disengaging the wheel 44 is pressed against a brake surface 5() yieldingly pressed inward toward the same by spring mountings4 51. The clutch sleeve 3 2 is operated by a swinging arm 52 fixed on a shaft 53 journaled transversely in the vmachine frame. The shaft 53 has fixed thereto a horizontally extendin arm 54 equipped at its outer end With a p1n engaglng in a cam slot 56 of a bar 57 guided for horizontal sliding movement at one side of the machine frame. The bar 57 also-controls the swinging of the arm 48 which governs the engagement of the friction clutch 43, for this purpose having a second cam slot 58 engaging a pin 59 on the outer end of an arm 60 which is v fixed to the shaft 49. The inner end of the bar 57 has pivoted thereto the lower end of alever 61 which is fulcrumed to the ma.-

' chine bed at 62 and and has its upper end equipped with gear teeth making a segment operating connection 63 with the lower end of a lever 64 pivoted to the bed at 65, the upper end of which is pivotally connected to the inner end of a rod 66 extending horizontally and slidably guided at one side of '68 shifting the bar 66 and hence the cam bar 57. It will be noted that the outline of the cam slot 58 is such that at .the beginning of the sliding movement of the bar 57 to the right as shown in Fig. 1` the pin 59 will begin to tra-vel downward. thus shifting the shaft 37 endwise at once. throwing out the driving clutch 43 and applying the brake 50. As this takes place the pin- 55 is moving along a neutral part of the slot 56 so that the clutch sleeve 32 is not shifted until after the prime power clutch43 is disengaged and the shaft 37 stopped. It will be noted that upon the stoppage of the shaft 37 and hence of the clutch head 34, the tendency to fur- Fther forward movement by momentum of the machine bed near the top thereof. The

the screws with their gears 27 27a, will itself ,f

tend to throw the clutch sleeve 32 out of engagement with the clutch head 34 both by reason of the inclined backs of the coperative clutch teeth and also by reason of the inclined or spiral formation of the teeth of the pinion 31 and the gears 27, 27a meshing therewith. To insure the complete throwing of the clutch sleeve 32 to a neutral position, however and also to reverse it, the pin 55 next encounters an active portion of the cam slot 56 as the bar 55 is moved farther to the right whereupon the clutch sleeve 32 is shifted to its limit of movement to the right in Fig. 2 engaging the clutch face 41 of the reverse driving gear 40. In practice the first described movement is usually produced by the automatic stop device including the stop lugs 70, 71, which thus automatically operates to throw out the driving clutch and stop the machine at the end of an operative movement of the draw head. Then the bar 64 being shiftedfarther to the right the draw head 14 is returned to initial position by power transmitted through the reverse gear 44. f

It is also practicable to employ the present improved arrangement of driving gears in a form wherein the screws are not rotated and in Fig. 5 I show such a form ofthe in-l vention. In this figure the draw head 140 has ixedly soeketed therein as by cotter pins or the like, theinner ends of the screws 180, 180% These screws extend inward through bearing bushings 73 of the transverse backing web 230 of the machine bed. Within the gear housing 12() at the rear of the machine bed are mounted rotary nuts 190 engaging the screws 180, 180e, these nuts having keyed or otherwise rigid therewith driving gears 270, 270u set one behind the other in like manner as the gears 27, 27 a, and both driven from a single elongated pinion in like manner as the pinion 31. The nuts 190 which are relatively long have bearings in sleeves 74 rigid with the machine frame housing 12 and at the inner ends of said nuts antifriction roller bearings 75 are interposed to take the operative thrust against the backing web 230 in like'manner as similar antifriction bearings provided in the first described form. In this form of the invention the screws 180, 180, project through the machine housing 12 and outward according to the length of travel required of the draw head. It is to be observed that in both forms ofthe invention described the driving gearing is simple yet powerful and eiiicient, and both screws being driven direct-ly from the common driving pinion 31, the. screw movements are better synchronized than is the case where one screw is driven from the driving gear of the other screw with the more or less back-lash incident thereto as has heretofore been usual. Further it is to be noted that the positive forward and reverse driving clutches including the clutch vfaces formed at the ends of the clutch sleeve 32 are thrown into engagement only when the power frictionclutch 43 is disengaged and the driving shaft 37 stationary.

For holding the work in operative position, the vertical' front face 11 vof the machine bed 'is equipped with an undercut slab 76 to which is fitted for vert-ical adjustment a face plate 77, such adjustment belng .effected by having adjusting screws 78 1mpinge on the top and bottom of the .face plate, these screws being fitted foradjustment in overhanging flanges of heads 79 bolted or otherwise secured to the slabs 76. The face plate is also preferably equlpped with an annular groove 8() on its outer face concentric with the central passage 81 thereof, for the purpose of receivrnga centering rib of the work holder to aid 1n correctly locating the work wlth reference to the Abroach. A suitable lubricatmg system is provided including piping 82 with a discharge nozzle 83 delivering lubricant adjacent to and just .over the working area of the broach. I am aware that the invention may be embodied in other specific forms as to its several features as set forth without departing from the s irit or essential attributes thereof, and therefore desire the present embodiment to be considered as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the sco e of the invention;

aving described my invention, what I claim as new and desire to secure by Letters Patent is 1. Broach operating mechanism, comprising a broach draw head, spaced apart operating screws therefor each. having fixed at its inner end a relatively large driving gear, said gears being offset laterally with respect to each other and overlapping, and driving mechanism including a relatively small elongated pinion engaging both said gears to drive them and operate said screws in unison.

2. Broach operating mechanism, compris- 'ing a breach drawhead, spaced apart operating screws therefor engaged therewith, each screw having fixed at its inner end a relatively large driving gear, said gears overlapping and laterally offset with respect to each other, and a relatively small elongated driving pinion engaging both said gears to drive them and operate said screws in unison, said pinion having inclined teeth for the purpose stated.

3. Broach operating mechanism, comprising a breach draw head, spaced apart operating screws therefor engaged therewith, each screw having fixed at its inner end a relatively large driving gear, said gears overlapping and laterally offset with respect 4to each other, a relatively small elongated driving pinion engaging both said gears4 to drive them and o erate said screws in unison, and driving mec ianism for said pinion including a forward drive connection, a reverse drive connection and a clutch device shiftable to engage either of said connections 'at will.

4. Broach operating mechanism, comprising a broach draw head, spaced apart operating screws therefor engaged therewith, each screw having fixed atits inner end a relatively large driving gear, said gears overlapping and laterally offset with respect to each other, a relatively small elongated driving pinion engaging both said gears to drive them and operate said screws in unison, and driving mechanism for said inion including a forward4 drive connection, a reverse drive connection and a clutch device shiftable to engage either of said connections at will, said clutch device and said elongated pinion being formed as a unit and said elongated pinion'having inclined teeth for the purpose stated.

5. Broach operating mechanism, compris-A ing a broach draw head, spaced apart operating screws therefor, relatively large actuating gears fixed on the ends of said screws mounted adjacent each other laterally offset mechanism including a relatively small 10.

elongated pinion engaging both said gears .to drive them and operate said screws in unison. n

In testimony whereof I have signed my name to this slicification.

ALPH R. LAPOINTE. 

